cams_ads

Live CAMS radiation via ADS (Copernicus Atmosphere Data Store). Retired (``runnability.RETIRED``): the same ``cams-solar-radiation-timeseries`` request as :class:`CamsRadiationCdsConnector`, written under a second source_id and the bare ``ghi`` variable, so one quantity became two series. ``cams_radiation`` is canonical - it carries the ``cams_*`` variable ids the catalogue registers and is the one the nightly worker runs. Kept registered so its code, tests and any rows already written stay readable.